Together with GodelsTheorem, BertrandRussell's idea of peer review, Popper's notion of falsifiability changed modern notions of proof and the ScientificMethod. Popper accepted Hume's critique of induction, taking the view that no matter how many times the same result occurs in an experiment there always remains the possibility that the next result will contradict this (as such truth assumes a provisional character). Under such circumstances a theory cannot be verified, merely assigned a truth value. However, the falsification of a theory may be regarded as conclusive whereas verification may not.
Popper is also noteworthy for having applied these observations beyond the realms of pure science. For example, communism had always described itself as being scientific, but was criticised by Popper for failing to pay heed to instances where its tenets had been falsified. Since communism failed to fulfill its predictions it has since fallen into the realm of belief - see OnCommunism. In particular, Popper regarded communist claims to predict social trends as being spurious. Since such events could not be predicted the only sensible approach is to proceed through continual scrutiny; to Popper the notions of democracy and rights can almost be considered as being analagous to peer review.